As standards for plumbing products are made more stringent, there is a need to provide protection for plumbing products in a solar water heater environment, particularly once water in a tank heated by solar means has reached its desired temperature. Unlike electrical or gas hot water systems which have their elements or gas burners turned off when the desired temperature is reached, a solar collector associated with a solar water heater will continue to gather solar energy.
In continuing to gather solar energy the solar heating system and its associated plumbing could be compromised by over heating.
The applicant does not concede that the prior art discussed in the specification forms part of the common general knowledge in the art at the priority date of this application.